Yesterday it was reported that
Joe Girardi has had conversations with Alex Rodriguez about playing first base. We don't know how extensive those talks were, but it's certainly something to consider since a second first baseman would be a very good thing for the Yankees to acquire. And that's even if they bring Chase Headley back, because Chase would likely be the regular third baseman.
"I'm a Yankee again, and I will play regularly at 3B? Sweet!"
If something were to happen to Mark Teixeira, like... say... he nicks his face while shaving and needs a day to recover from it, then what does Girardi do? Thanks to Martin Prado, it actually wouldn't be that difficult. But keep in mind that somebody from the bench is going to come into the game. And I think it's a safe bet that the offense would get weaker as a result, because it's very rare that a bench player will out-hit a regular.
Not to mention that the defense would likely take a hit.
For example, to start, let's say the Yankees bring back Chase Headley. While losing a gold glover in Teixeira at first base would hurt, they could probably get by just fine with Headley there. But if Chase were the regular third baseman, and he were replaced there by Alex Rodriguez, then that would be a much bigger problem. Basically, the defense would go down a little at first base, and would go down a lot at third.
So what do they do to combat that? Play Alex Rodriguez at first base regularly, while Mark Teixeira is the primary designated hitter.
In this scenario, if Mark Teixeira gets a mosquito bite doing the game and needs to take the rest of the night off, you can do so many things, as anybody can DH. And say Alex Rodriguez gets hurt, then just move Tex to 1B. Of course, assuming Tex started the game as the DH, then a pitcher is going to have to hit as you lose the DH when he changes positions. That's not a good thing, but chances are that move wouldn't happen until later in the game when you can pinch-hit for a reliever when that spot in the lineup comes up.
You can't avoid an offensive hit, but with ARod at 1B and Tex at DH you simplify things, and the defensive hit is minimized.
Let's look at things another way...
Alex Rodriguez is not the poster child for great health. In 2011 he missed 39 games for his right knee, missed 36 games due to fracturing his left hand in 2012, and of course had hip surgery in 2013. But he hasn't had any further problems with his right knee, his left hand recovered just fine from the fracture, and he just spent the entire 2014 season resting and recovering from that hip surgery. At this point, ARod should be fairly healthy.
On the other hand you have Mark Teixeira. In 2013 Mark missed 147 games due to tearing a tendon sheath in his right wrist, and has had problems with that wrist since (including missing 5 games this past season). On top of that, this past season, he had to go on the 15-day disabled list because of straining his right hamstring. Furthermore, this past season, he missed time due to issues involving his left wrist, fingers of his left hand, back, trunk, and groin.
The bottom line is that Mark Teixeira is a much bigger question mark, as far as health, than Alex Rodriguez. Because of that, it might be a good idea to make it a goal that Alex becomes the regular first baseman, while Tex becomes the regular DH.
"I know... I know... I have to stay healthy and play right field regularly."